pathogens

Question 1

What Determines the Outcome of Disease

Answer 1

1. Pathogen: Number of pathogens, Pathogenicity
2. Host: Defence capabilities of host, Immunocompromised

Question 2

Pathogen

Answer 2

• Infectious agent that is capable causing disease

Question 3

Host

Answer 3

• Any organism that carries another organism

Question 4

Infectious Disease

Answer 4

• A disease that is caused by a pathogen or infectious agent and can be transmitted from one organism to another

Question 5

Virus

Answer 5

• Contains DNA or RNA
• Intracellular obligate pathogen
  E.G. Influenza

Question 6

Steps of Virus

Answer 6

1. Virus targets a specific cell
2. Viral genetic material inserted into host cell
3. Genetic material replicate in DNA replication
4. Cell lysis
5. Virus spread to more cells

Question 7

Prion

Answer 7

• Misfolded protein
  1. Abnormal prion induced misfolding in normal prions
  2. Damages the nervous tissue
  3. Transmissible spongiform encephalopathy
  E.G. Kuru Disease

Question 8

Bacteria

Answer 8

• Prokaryotic organism
• Can be intracellular or extracellular
• Treated with antibiotics and disinfectant
  1. Rapidly multiply by binary fission
  2. Release mycotoxins
  3. Toxin cause disease
  E.G. Samonella

Question 9

Protozoa

Answer 9

• Unicellular eukaryotes
  E.G. Malaria

Question 10

Steps of Protozoa

Answer 10

1. Attaches to intestine
2. Prevents nutrient absorption

Question 11

Fungi

Answer 11

• Unicellular eukaryotes
  E.G. Athletes Foot

Question 12

Steps of Fungi

Answer 12

1. Survive on surface of skin
2. Release mycotoxins

Question 13

Microparasite

Answer 13

• Multicellular eukaryotes
• Can be pathogens and vectors
  E.G. Tapeworm, Aphids

Question 14

TRANSMISSION (ALL PATHOGENS EXCEPT PRIONS)

Answer 14

• Vector transmission
• Contact with infected surfaces
• Contaminated food and water

Question 15

TRANSMISSION: PRIONS

Answer 15

• Contaminated surgical tools
• Eating meat containing abnormal protein
• Inheritance

Question 16

Epidemic

Answer 16

• Widespread occurrence of an infectious disease in a community at a particular period of time

Question 17

Types of Transmission

Answer 17

• Direct Contact
• Indirect Contact
• Vector Transmission

Question 18

Type of Transmission: DIRECT

Answer 18

• Vertical Transmission: Genetic
• Horizontal Transmission: Anything else
  E.G. touching, kissing, bitin

Question 19

Type of Transmission: INDIRECT

Answer 19

• Fomites
  E.G. Airborne, surgical equiptment

Question 20

Type of Transmission: VECTOR

Answer 20

• Disease is spread through another animal

Question 21

Koch’s Postulates

Answer 21

1. Suspected causative agent must be absent from all healthy organisms but present in all diseased organisms
2. Suspected causative agent must be isolated from the diseased organism and grown in pure culture
3. Suspected causative agent must cause the same disease when inoculated in a healthy organism
4. Suspected causative agent must then be reisolated from the inoculated diseased organism